As operators of the most popular search engines roll out more services that require user registration, industry observers and privacy advocates say it's become more feasible to associate a particular query with an individual.

...Chris Hoofnagle, West Coast director of the Electronic Privacy Information Center, is particularly wary of Google's growing dominance in search and its expansion into other areas, like its free e-mail service, Gmail, and its social-networking website, orkut.com.

"Many people use Google all day, plus Gmail and orkut," he said. "It will supplant Microsoft as the company that has its finger on the infrastructure of our data."

Another worrisome specter for privacy advocates is Google's use of tracking cookies. According to Hoofnagle, Google's privacy policy still reserves the right to use a single cookie across product lines, including web searches, e-mail and other applications.

This article hits all the general privacy issues related to searching, which I'vecommented onbefore. It's promising, however, that this vital disucssion is reaching the mainstream media.